1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to dynamic gain adjustment based on brightness, and more particularly, to dynamic gain adjustment based on brightness can amplify or attenuate high frequency components of an input video signal by dynamically varying a gain that is applied to a peaking algorithm block for picture quality improvement in a video processing device, such as a digital television (TV), based on an average picture level (APL) of the input video signal.
2. Description of the Related Art
A peaking algorithm block has been used in a video processing devices for the purpose of picture quality improvement.
FIG. 1 is a block diagram illustrating the construction of a related art peaking algorithm block.
The related art peaking algorithm block includes a high pass filter (HPF) 11, a coring unit 12, a gain unit 13, a mixer 14, and a limiter 15.
Based on this related art peaking algorithm block, the high pass filter 11 separates high frequency components from an input signal, and the coring unit 12 removes noise components from the high frequency components. The gain unit 13 then amplifies or attenuates the high frequency components applied from the coring unit 12, and the mixer 14 mixes the amplified or attenuated high frequency components with the input signal. The limiter 15 limits a peaked part of the mixed signal.
The related art peaking algorithm block has been used to improve the luminance frequency characteristic of an input video signal. High frequency components are extracted from the original signal through the high pass filter 11, the extracted high frequency components are amplified or attenuated through the gain unit 13, and then the amplified or attenuated high frequency components are mixed with the original signal through the mixer 14.
However, since this related art peaking algorithm block operates only based on the frequency, irrespective of the brightness of a video signal, the same gain value is continuously applied to the signal, irrespective of whether the brightness of the video signal is high or low. This may cause unwanted results, such as saturation of the video signal.